A number of variants of devices for generating a laser light beam have been known in actual practice for years. Merely by way of an example, mention is made here of German patent DE 196 33 185 C2, which discloses a polychromatic point light source for a laser scanning microscope. Here, the radiation from a total of four sources of laser light is coaxially combined by means of a recombiner unit. Via an appropriate connection, an optical fiber leads to a laser scanning microscope, where the recombined laser light beam is coupled in with several wavelengths or with several laser lines in the form of a light point source.
The prior-art devices are problematic because the sources of laser light employed often differ from each other in terms of their mode of operation and they usually come from different manufacturers. Moreover, the sources of laser light often have different physical dimensions, in addition to which they have different electrical specifications, which makes it extremely difficult for the user to individually compose a laser light beam comprising several laser lines of individual sources of laser light. Consequently, adding a new source of laser light to an existing system or even merely replacing a single source of laser light entails a great deal of effort and usually can only be done by trained personnel. It is likewise problematic that, when a source of laser light is replaced, it is generally necessary to replace not only the laser light source itself, but also mechanical parts, optical filters, electrical interfaces, power packs, etc.
Particularly in conjunction with the illumination configuration found in confocal microscopy, in extreme cases, it is even unavoidable that the confocal microscope or at least parts of it will have to be sent to the manufacturer. In any case, however, a special service call by the device manufacturer will certainly become necessary for maintenance and retrofitting work.
Especially large-scale imaging facilities often tend to have several identical or similar confocal microscopes but these are frequently equipped with different sources of laser light. Then, it is frequently the case that only a very specific confocal microscope is suitable for a specific experiment since only that microscope has the laser light sources needed for the experiment in question. In actual practice, this often leads to certain bottlenecks in the utilization of the microscopes, particularly when several experiments are supposed to be carried out at the same time which, due to the concrete requirements made in terms of the illumination, need the same confocal microscope. It is also often the case that, for a particular observation, an inverted microscope is needed but the requisite combination of laser light sources is only available in an upright microscope. The retooling of the microscope that is then necessary entails a considerable expenditure of time and effort on the part of the user.